The Fresh Loaf

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Ovenspring, again, and steaming method effects

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davidg618's picture
davidg618

Ovenspring, again, and steaming method effects

I recently baked, for the third time, two sourdough boules, which besides the primary purpose: Eating, tested the effects of slashing, and steaming methods, and the behavior of a new starter. The latter is posted elswhere (Purchased Dried Starter Reactivation Survey).


These loaves were slashed identically, placed in the oven simultaneously, and swapped position after 15 minutes of steaming. The ovenspring realized is shown here,



and from this placement the loaves look acceptably identical. But...



...this is the position they were initially placed in the oven. (Note the asymmetric ovenspring outside-to-center of both loaves. 


I normally create steam with a towel-lined half-sheet pan, wetted with boiling water, and placed below the baking stone. This time, thinking I could direct the steam more toward the edges of the stone and, therefore, better direct the maximum volume of the steam upward toward the loaves, I rolled two small towels and placed them on the extreme ends of the half-sheet pan. 


Two of our regular problem analysts, David and Eric, have argued steam condensing on the bottom of a baking stone causes the stone's surface to cool, and effects ovenspring. I've been a bit skeptical, but I am no longer. It is evident that the rolled towels did focus the steam's rise. but the seventeen-inch pan, below a twenty-inch baking stone created an asymmetric cooled surface on the stone, as is evidenced by the lesser ovenspring on the left and right sides of the left and right loaf respectively. 


Subsequently, I tried placing the pan above the loaves (I've tried it before), rather than below the stone (and the loaves), but I'm still disappointed with the results. I've returned to steaming from below, using a half-sheet pan fully-lined with wetted towels. The ovenspring is again uniform across the loaves, but I suspect reduced from what it could be, due cooling from condensing steam across the entire bottom of the baking stone.


I'm once again rethinking my steaming process. I like the control the wetted towel vs. lava rocks gives me--I can remove the pan safely when steaming time is completed, but I don't want the stone cooling effect. I'm thinking of fabricating and placing two narrow aluminum troughs in the spaces between the stone and the oven's wall, and filling them with wetted towels five or six minutes before loading the loaves. This, of course, will interrupt the heat convection paths on the sides of the stone, but I'm not certain, nor can I guess, how that will effect the baking.


Stay tuned;-)


David G.



Comments

ramat123's picture
ramat123

I've started using steaming below the stone a months ago and the results are much better. I'm heating the oven for at least 45 minutes with the stone. Then. 10 minutes before putting the loves in I'm adding a large bowl with boiling water. When putting in the loaves I see a much better oven spring and to my understanding the loves gets out the same. I would love to hear about better options. What do they do in professional baking?

mrfrost's picture
mrfrost

http://picasaweb.google.com/burn1cesharpe/ATKRollsAndLoaves#5454222156213267490


If the video is fuzzy, click on "view HQ video" on upper right of player.

ehanner's picture
ehanner

David G,


I see what you are talking about. I also see the back of your oven is considerably hotter than the front, which is common. After looking at your photo's, I come to the conclusion that your dough is not being steamed equally, left to right. The center side of both loaves is being under served.  Honestly the results are pretty darn good for a home oven. You can tweak this till the cows come home but there are only so many things you can do to change the heat patterns of a home oven.


Eric

davidg618's picture
davidg618

I think that's only in the conventional mode, which I use during steaming. I preheat, and finish baking after removing the steam source in the convection bake.


I'm going to keep tweaking, first because it's kinda fun, and secondly to get things as consistent as possible, knowing full well I'm pushing uphill;-)


Your comments have been very helpful.


David G

tananaBrian's picture
tananaBrian

Very interesting stuff!  I can't say from vast experience, but I suspect Eric is right about only being able to do so much and no more.  That said, I wonder if the stone cooling from the steam (a couple hundred degrees cooler than the preheated oven) could be countered by first preheating the oven to a hotter temperature, say 20 F hotter than you will bake at, then right after adding the steam and closing the door, adjust the temperature back down to what it should be.  The oven cooled from opening the door and the stone cooled from the steam, but both were too hot to begin with ...the net hopefully being a right-temperature stone and oven.  I wonder if that would work?


BTW, I place a thermometer on the center of my 3/4" thick Fibrament stone and it takes a full hour for it to barely reach the oven temperature.  For example, if my oven preheats to 460 F and starts cycling on and off to maintain that temperature, the thermometer on the center of the stone only reads about 410 F.  After 45 minutes or so, it's up to about 450 F.  It won't hit the full 460 F for at least 60 minutes from when I turned the stove on.  Nowadays, I don't put bread into the oven until that thermometer reads the full and correct temperature that I was aiming for.


 


Brian


 

davidg618's picture
davidg618

I already preheat my stone (Fibrement) to the maximum temperature my oven allows: 550°F; and I usually preheat for at least one hour.


David G

Supes On's picture
Supes On

I finally "solved" the steaming problem in my home oven by adding a copper tube down the oven vent and injecting steam with one of those steam cleaner appliances (don't remember the brand name).  That way I can get the  bread onto the hot stone quickly and close the door without losing too much heat.  Then I add steam down the copper tube.  Since some can eventually escape out the vent I reapply steam a couple times in the first 3 to 5 minutes.


The steam does not come out under the stone so there is no cooling.  It seems to work for me, but I will admit it took some doing to get the tube inserted.


I now do most of my baking in my outdoor wood-fired oven.  I use the same steam appliance to add steam to that oven since I rarely fill it with enough bread for it to create its own steam.

ramat123's picture
ramat123

Understand this thread and imperssed by the depth of the knowledge, do you know what's a professional oven characteristic that solves these problems? Do you know how the steaming system works in pro-ovens?

ananda's picture
ananda

Hi


In a deck oven, steam is usually injected under pressure directly into the chamber.   this is an effective method, but one which can be quite inefficient as it can take too long to refill and re-heat the water supply ready for the next steam burst required.


In a rack oven the steaming system is way more effective.   I suppose they've got to be good for something; personally I hate the things as they don't utilise conducted heat.   Anyway, wheel the rack into the oven and shut the door.   Most modern rack ovens will be programmable, so the steam setting will form part of each programme.   What happens is that cold water is allowed to run down a sequence of channels on one of the side walls of the chamber.   These have clay tubes within them to heat the water as it drops down.   The turntable will move round straightaway, but the burners will not kick in for a short time.   The oven needs to be idled hot for this process, as a considerable amount of heat is lost due to the amount of cold water and metal being put into the oven.   When the fans and the burners kick in a tremendous amount of steam is created which aids the convection system well.   The damper will open automatically as programmed to exhaust the steam from the chamber at the correct point in the baking cycle.   As I say, I like my conduction when it comes to baking; you can't substitute for sitting your products directly on the heat source - good steam system or not!


Hope this helps


Best wishes


Andy

ramat123's picture
ramat123

And now for the follow up question: are there any rack ovens you reccoment for a small size bakery (home bakery that sells about 100 loaves a week).

ananda's picture
ananda

I wouldn't recommend you buy a rack oven if you gave me a £1000!


Sorry


Andy

ramat123's picture
ramat123

Do I have to get the steam out after the time it's in the oven?now the bowl with the boiled water but the steam that is running in the oven? Is that importatant or it will all get catch in the dough?

davidg618's picture
davidg618

I'm not an expert, just a tinkerer, but it seemed to me I'd get a drier crust if I eliminated the steam after it had done its job aiding oven spring. Consequently, I remove the steam source at the end of the prescribed time.


I also read a TFL posting this morning (but I don't remember where) stating steam inhibits browning, and, therefore, he/she removes the steam resulting in better browning.


David G.

ananda's picture
ananda

Hi David,


I think you have the right idea to remove the steam source later rather than sooner.


But I think this post really highlights the difference between commercial process and homebaking, and Mr Frost is looking at this in the post below too.


A commercial oven will have a much stronger seal on the oven door, and most likely a more sophisticated way to introduce steam into the oven.   The latter is actually not essential to what I want to mention here, although it really helps in terms of initial oven spring by keeping the surface of the loaves from drying out for a longer time period.


However, baking in a pressurised environment actually has a significance all of its own.   This is important for all types of baking...cakes, scones, breads etc.   It is achieved as moisture is driven off the baking products as steam which is retained within the oven chamber giving a pressurised environment.


In a commercial oven, the pressure is released when the damper is opened, thus moisture is exhausted from the oven.   I agree with you, that this should take place towards the end of the whole baking cycle, as the Maillard Reactions conclude.


It's very hard to bake in a domestic oven the same way baking takes place in commercial ovens.   I think Reinhart said in Bread Bakers Apprentice that 80% was in the mixing of the dough, and 20% in the heat treatment applied.   Sometimes I'm not sure I agree with this comment at all.


Maybe that is a good point for us to reflect on?


Best wishes


Andy

zorrambo's picture
zorrambo

I am new to breadmaking but I was taught to spray the walls of the oven with a squirt bottle and then close the oven door quickly. It seems a very simple method of steaming and fairly easy to control. If I want more steam I can add some. If I want to stop the steaming I just open the oven door briefly to let the steam escape. Please tell me why noone mentions this method and what are the downsides.

mrfrost's picture
mrfrost

The method is actually mentioned quite often. However, it is also believed by many that the method does not produce enough steam. Even though most methods do not duplicate the steaming of professional ovens, many think there are more effective methods that spraying on it's on.